1. Field of the Invention
The present invention relates to weather stripping for the window pane of a motor vehicle, and particularly relates to portions of the stripping which couple the upper and lower portions of front and rear vertical stripping sections to each other.
2. Description of the Prior Art
As shown in FIGS. 3 and 4, a conventional weather strip 1 for the window pane of a front door D of a motor vehicle is constructed so that the upper ends of the front and rear vertical parts 2 and 3 of the weather strip are coupled to each other by the oblique pillar and roof part 4 thereof. The extruded upper and lower portions 11 and 21 of the vertical parts 2 and 3 are coupled to each other by die-molded portions 9. The oblique pillar and roof part 4 is extruded and coupled to the front and the rear vertical parts 2 and 3 by die-molded portions 6 and 7.
The cross section of each of the upper portions 11 is asymmetric. When each of the upper portions 11 is fitted in a pane channel C as shown in FIG. 5 or 6, a pane housing groove 15 is defined by the inner, intermediate and outer walls 12, 13 and 14 of the upper portion to make the cross section thereof nearly U-shaped. A curved seal lip 16 projects from the inner wall 12 into the pane housing grooves 15 to urge a door pane G outwards with regard to the motor vehicle. A nearly straight seal lip 17 projects from the outer wall 14 to hardly urge the pane G inwards with regard to the motor vehicle, or a curved small seal lip 18 projects from the outer wall 14 into the pane housing groove 15 to slightly urge the pane G inwards with regard to the motor vehicle. The seal lip 17 or 18 projecting from the outer wall 14 is caused to slightly urge the pane G inwards with regard to the motor vehicle. In this manner, the distance between the outer surface of the pane G and that of the sash S of the door D is minimized to reduce a wind noise and improve the appearance of the door (and also make the outer surfaces of the vehicle almost flush with each other).
On the other hand, the cross section of each of the lower portions 21 is symmetric. A pane housing groove 15 is defined by the inner, intermediate and outer walls 12, 13 and 14 of each of the lower portions 21 in the same manner as each of the upper portions 11, as shown in FIG. 7. Curved seal lips 26 having the same form as each other project from the inner and outer walls 12 and 14 of each lower portion 21 into the pane housing groove 15. Each lower portion 21 is provided with the symmetric cross section constituted by the walls 12, 13 and 14 and the curved seal lips 26 as described above. The pane G is held by the lower portion 21 and the lower portion is easily fitted in the pane channel C.
The die-molded portions 9 between the upper and the low portions 11 and 21, respectively, are shaped so that the cross-sectional form of each upper portion 11 including the seal lips 16 and 17 (or 18) is gradually changed into that of the corresponding lower portion 21. In other words, the die-molded portions 9 are constructed so that seal lips, which are located in sliding contact with the door pane G, project from the inner and outer walls of the die-molded portions.
As for the above-described construction, the pane contact surfaces of the seal lips (especially, the curved seal lips extending into the pane housing groove 15) of each die-molded portion 9 need to be subjected to a treatment such as urethane paint application and electrostatic hair planting in order to reduce the resistance to the sliding contact and enhance the anti-wearing durability of the pane contact surfaces. This results in increasing the number of manufacturing steps for the weather strip. That is a problem.